铝-硅复合还原氮化合成矾土基β-SiAlON的研究  

Investigation on Synthesis of Bauxite Based β-SiAlON by Using Aluminum/Silicon Reducing Agent

作　　者：李素平[1] 郭艳芹[1] 钟香崇[1] 

机构地区：[1]郑州大学高温功能材料河南省重点实验室,郑州450052

出　　处：《非金属矿》2008年第3期15-17,共3页Non-Metallic Mines

基　　金：河南省教育厅重大科技攻关项目(20014300020)

摘　　要：以高铝矾土(Al2O3含量68%)、金属铝粉和硅粉为原料,按一定比例配料、混料,将混合均匀的试样,在1100℃～1550℃氮化处理6h,然后测定氮化试样的重量变化率,借助XRD、SEM及EDS等手段,分析试样的物相组成、显微结构和微区成分。对比单一还原剂铝、硅的反应过程,研究铝-硅复合还原剂还原氮化合成矾土基β-SiAlON的反应过程及机理。结果表明:1100℃,铝粉氮化生成AlN,同时铝粉还原SiO2生成Si;1200℃,硅粉氮化生成Si3N4,同时有硅粉、氮气和SiO2反应生成Si2N2O;1300℃～1350℃,Si3N4通过固溶逐渐转化为β-SiAlON,同时有少量硅粉发生还原反应;1400℃～1550℃,试样进入固溶阶段,β-SiAlON量逐渐增多,1500℃达最佳值,生成的β-SiAlON为颗粒状和短柱状。与单一还原剂相比复合还原剂生成β-SiAlON的含量相对较高,晶体发育较好。The process of synthesizing bauxite based β-SiAION by using aluminum/silicon reducing agent was studied. Specimens prepared by mixing bauxite （Al2O3 68%）, aluminum and silicon were nitrided at 1100℃ 1550℃ for 6h. The mass change ratios of the specimens were determined. Phase composition and microstructure of some specimens were examined by XRD, SEM and EDS. The results were compared with those of specimens using Al and Si separately as reducing agent. It is found that at 1100℃ Al reacts with N2 to form AIN and AI reacts with SiO2 to form Si; At 1200℃ Si is nitrided to form Si;N4 and Si reacts with N2, SiO2 to form Si,N：O; From 1300℃ to 1350℃, some Si takes part in reduction reaction and the formation of SiAION starts; At 1450℃- 1550℃, there is noticeable increase in β-SiAION formation, the appropriate nitriding temperature is 1500℃. The amount of β-SiAION formed is higher and crystale growth is better than that of single reducing agent.

关 键 词：铝矾土 Β-SIALON 铝-硅复合还原剂 还原氮化反应 

分 类 号：TQ175[化学工程—硅酸盐工业]